This invention is directed to a process for printing in which high quality prints are obtained from images of negligible relief without the requirement of a dampening or fountain solution.
In order to be suitable as relief image carriers, the master image must have the proper depth. This depth is the distance between the level of the printing surface and the non-printing areas of a master. Line engravings that are to be used on high-finished papers are usually etched to a depth of approximately 0.020 inch or 500 microns. Engravings made for flexographic printing and for printing on rough papers have a depth of 0.040 inch and more or 1000 microns and more. (The Printing Industry by Victor Strauss (1967) published by the Printing Industries of America, Inc.).
Because of the relatively large image relief required in conventional masters, they are difficult to prepare as well as costly and time consuming to prepare. Additionally, high relief resilient, or elastomeric images produce smeared, unsharp or poorly defined images because of lateral shifting, sometimes called "squirm" in flexographic printing. Consequently, a method of printing employing masters having images of low relief, which could be rapidly and inexpensively prepared, and could print with better image definition would be highly desirable and in accordance with this invention such a method is provided.